I could understand posing atop the tower, or even atop the stairwell tower, if there's access to the outside, because those are flat surfaces - but that photo was taken on the steeply slanted portion of the roof that's over the Master Bedroom/Gallery. Not having been up there myself, maybe somehow in reality it's not as dangerous as it would appear to be, but it sure as hell would seem to be dangerous...
As for some of the stills that are completely unrelated to the script, I do like the ones of Nancy Barrett and Chris Pennock goofing around at the real Rose Cottage and elsewhere on the Lyndhurst estate:
But those aren't in character...